Bug Summary

File:projects/compiler-rt/lib/scudo/../sanitizer_common/sanitizer_allocator_size_class_map.h
Warning:line 154, column 23
The result of the left shift is undefined due to shifting '256' by '1073741820', which is unrepresentable in the unsigned version of the return type '__sanitizer::uptr'

Annotated Source Code

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clang -cc1 -triple i386-pc-linux-gnu -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name scudo_allocator.cpp -analyzer-store=region -analyzer-opt-analyze-nested-blocks -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=cplusplus -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -analyzer-config-compatibility-mode=true -mrelocation-model pic -pic-level 2 -mthread-model posix -mframe-pointer=all -fmath-errno -masm-verbose -mconstructor-aliases -munwind-tables -fuse-init-array -target-cpu i686 -dwarf-column-info -debugger-tuning=gdb -ffunction-sections -fdata-sections -resource-dir /usr/lib/llvm-10/lib/clang/10.0.0 -D _DEBUG -D _GNU_SOURCE -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -D clang_rt_scudo_dynamic_i386_EXPORTS -I /build/llvm-toolchain-snapshot-10~svn374877/build-llvm/projects/compiler-rt/lib/scudo -I /build/llvm-toolchain-snapshot-10~svn374877/projects/compiler-rt/lib/scudo -I /build/llvm-toolchain-snapshot-10~svn374877/build-llvm/include -I /build/llvm-toolchain-snapshot-10~svn374877/include -I /build/llvm-toolchain-snapshot-10~svn374877/projects/compiler-rt/lib/scudo/.. -U NDEBUG -D GWP_ASAN_HOOKS -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/x86_64-linux-gnu/c++/6.3.0/32 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/i386-pc-linux-gnu/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/c++/6.3.0/backward -internal-isystem /usr/local/include -internal-isystem /usr/lib/llvm-10/lib/clang/10.0.0/include -internal-externc-isystem /include -internal-externc-isystem /usr/include -O3 -Wno-unused-parameter -Wwrite-strings -Wno-missing-field-initializers -Wno-long-long -Wno-maybe-uninitialized -Wno-comment -Wno-unused-parameter -Wno-variadic-macros -Wno-non-virtual-dtor -std=c++14 -fdeprecated-macro -fdebug-compilation-dir /build/llvm-toolchain-snapshot-10~svn374877/build-llvm/projects/compiler-rt/lib/scudo -fdebug-prefix-map=/build/llvm-toolchain-snapshot-10~svn374877=. -ferror-limit 19 -fmessage-length 0 -fvisibility hidden -fvisibility-inlines-hidden -fno-rtti -fgnuc-version=4.2.1 -fobjc-runtime=gcc -fdiagnostics-show-option -vectorize-loops -vectorize-slp -analyzer-output=html -analyzer-config stable-report-filename=true -faddrsig -o /tmp/scan-build-2019-10-15-233810-7101-1 -x c++ /build/llvm-toolchain-snapshot-10~svn374877/projects/compiler-rt/lib/scudo/scudo_allocator.cpp

/build/llvm-toolchain-snapshot-10~svn374877/projects/compiler-rt/lib/scudo/scudo_allocator.cpp

1//===-- scudo_allocator.cpp -------------------------------------*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8///
9/// Scudo Hardened Allocator implementation.
10/// It uses the sanitizer_common allocator as a base and aims at mitigating
11/// heap corruption vulnerabilities. It provides a checksum-guarded chunk
12/// header, a delayed free list, and additional sanity checks.
13///
14//===----------------------------------------------------------------------===//
15
16#include "scudo_allocator.h"
17#include "scudo_crc32.h"
18#include "scudo_errors.h"
19#include "scudo_flags.h"
20#include "scudo_interface_internal.h"
21#include "scudo_tsd.h"
22#include "scudo_utils.h"
23
24#include "sanitizer_common/sanitizer_allocator_checks.h"
25#include "sanitizer_common/sanitizer_allocator_interface.h"
26#include "sanitizer_common/sanitizer_quarantine.h"
27
28#ifdef GWP_ASAN_HOOKS1
29# include "gwp_asan/guarded_pool_allocator.h"
30# include "gwp_asan/optional/backtrace.h"
31# include "gwp_asan/optional/options_parser.h"
32#endif // GWP_ASAN_HOOKS
33
34#include <errno(*__errno_location ()).h>
35#include <string.h>
36
37namespace __scudo {
38
39// Global static cookie, initialized at start-up.
40static u32 Cookie;
41
42// We default to software CRC32 if the alternatives are not supported, either
43// at compilation or at runtime.
44static atomic_uint8_t HashAlgorithm = { CRC32Software };
45
46INLINEinline u32 computeCRC32(u32 Crc, uptr Value, uptr *Array, uptr ArraySize) {
47 // If the hardware CRC32 feature is defined here, it was enabled everywhere,
48 // as opposed to only for scudo_crc32.cpp. This means that other hardware
49 // specific instructions were likely emitted at other places, and as a
50 // result there is no reason to not use it here.
51#if defined(__SSE4_2__) || defined(__ARM_FEATURE_CRC32)
52 Crc = CRC32_INTRINSIC(Crc, Value);
53 for (uptr i = 0; i < ArraySize; i++)
54 Crc = CRC32_INTRINSIC(Crc, Array[i]);
55 return Crc;
56#else
57 if (atomic_load_relaxed(&HashAlgorithm) == CRC32Hardware) {
58 Crc = computeHardwareCRC32(Crc, Value);
59 for (uptr i = 0; i < ArraySize; i++)
60 Crc = computeHardwareCRC32(Crc, Array[i]);
61 return Crc;
62 }
63 Crc = computeSoftwareCRC32(Crc, Value);
64 for (uptr i = 0; i < ArraySize; i++)
65 Crc = computeSoftwareCRC32(Crc, Array[i]);
66 return Crc;
67#endif // defined(__SSE4_2__) || defined(__ARM_FEATURE_CRC32)
68}
69
70static BackendT &getBackend();
71
72namespace Chunk {
73 static INLINEinline AtomicPackedHeader *getAtomicHeader(void *Ptr) {
74 return reinterpret_cast<AtomicPackedHeader *>(reinterpret_cast<uptr>(Ptr) -
75 getHeaderSize());
76 }
77 static INLINEinline
78 const AtomicPackedHeader *getConstAtomicHeader(const void *Ptr) {
79 return reinterpret_cast<const AtomicPackedHeader *>(
80 reinterpret_cast<uptr>(Ptr) - getHeaderSize());
81 }
82
83 static INLINEinline bool isAligned(const void *Ptr) {
84 return IsAligned(reinterpret_cast<uptr>(Ptr), MinAlignment);
85 }
86
87 // We can't use the offset member of the chunk itself, as we would double
88 // fetch it without any warranty that it wouldn't have been tampered. To
89 // prevent this, we work with a local copy of the header.
90 static INLINEinline void *getBackendPtr(const void *Ptr, UnpackedHeader *Header) {
91 return reinterpret_cast<void *>(reinterpret_cast<uptr>(Ptr) -
92 getHeaderSize() - (Header->Offset << MinAlignmentLog));
93 }
94
95 // Returns the usable size for a chunk, meaning the amount of bytes from the
96 // beginning of the user data to the end of the backend allocated chunk.
97 static INLINEinline uptr getUsableSize(const void *Ptr, UnpackedHeader *Header) {
98 const uptr ClassId = Header->ClassId;
99 if (ClassId)
100 return PrimaryT::ClassIdToSize(ClassId) - getHeaderSize() -
101 (Header->Offset << MinAlignmentLog);
102 return SecondaryT::GetActuallyAllocatedSize(
103 getBackendPtr(Ptr, Header)) - getHeaderSize();
104 }
105
106 // Returns the size the user requested when allocating the chunk.
107 static INLINEinline uptr getSize(const void *Ptr, UnpackedHeader *Header) {
108 const uptr SizeOrUnusedBytes = Header->SizeOrUnusedBytes;
109 if (Header->ClassId)
110 return SizeOrUnusedBytes;
111 return SecondaryT::GetActuallyAllocatedSize(
112 getBackendPtr(Ptr, Header)) - getHeaderSize() - SizeOrUnusedBytes;
113 }
114
115 // Compute the checksum of the chunk pointer and its header.
116 static INLINEinline u16 computeChecksum(const void *Ptr, UnpackedHeader *Header) {
117 UnpackedHeader ZeroChecksumHeader = *Header;
118 ZeroChecksumHeader.Checksum = 0;
119 uptr HeaderHolder[sizeof(UnpackedHeader) / sizeof(uptr)];
120 memcpy(&HeaderHolder, &ZeroChecksumHeader, sizeof(HeaderHolder));
121 const u32 Crc = computeCRC32(Cookie, reinterpret_cast<uptr>(Ptr),
122 HeaderHolder, ARRAY_SIZE(HeaderHolder)(sizeof(HeaderHolder)/sizeof((HeaderHolder)[0])));
123 return static_cast<u16>(Crc);
124 }
125
126 // Checks the validity of a chunk by verifying its checksum. It doesn't
127 // incur termination in the event of an invalid chunk.
128 static INLINEinline bool isValid(const void *Ptr) {
129 PackedHeader NewPackedHeader =
130 atomic_load_relaxed(getConstAtomicHeader(Ptr));
131 UnpackedHeader NewUnpackedHeader =
132 bit_cast<UnpackedHeader>(NewPackedHeader);
133 return (NewUnpackedHeader.Checksum ==
134 computeChecksum(Ptr, &NewUnpackedHeader));
135 }
136
137 // Ensure that ChunkAvailable is 0, so that if a 0 checksum is ever valid
138 // for a fully nulled out header, its state will be available anyway.
139 COMPILER_CHECK(ChunkAvailable == 0)typedef char assertion_failed__139[2*(int)(ChunkAvailable == 0
)-1]
;
140
141 // Loads and unpacks the header, verifying the checksum in the process.
142 static INLINEinline
143 void loadHeader(const void *Ptr, UnpackedHeader *NewUnpackedHeader) {
144 PackedHeader NewPackedHeader =
145 atomic_load_relaxed(getConstAtomicHeader(Ptr));
146 *NewUnpackedHeader = bit_cast<UnpackedHeader>(NewPackedHeader);
147 if (UNLIKELY(NewUnpackedHeader->Checksum !=__builtin_expect(!!(NewUnpackedHeader->Checksum != computeChecksum
(Ptr, NewUnpackedHeader)), 0)
148 computeChecksum(Ptr, NewUnpackedHeader))__builtin_expect(!!(NewUnpackedHeader->Checksum != computeChecksum
(Ptr, NewUnpackedHeader)), 0)
)
149 dieWithMessage("corrupted chunk header at address %p\n", Ptr);
150 }
151
152 // Packs and stores the header, computing the checksum in the process.
153 static INLINEinline void storeHeader(void *Ptr, UnpackedHeader *NewUnpackedHeader) {
154 NewUnpackedHeader->Checksum = computeChecksum(Ptr, NewUnpackedHeader);
155 PackedHeader NewPackedHeader = bit_cast<PackedHeader>(*NewUnpackedHeader);
156 atomic_store_relaxed(getAtomicHeader(Ptr), NewPackedHeader);
157 }
158
159 // Packs and stores the header, computing the checksum in the process. We
160 // compare the current header with the expected provided one to ensure that
161 // we are not being raced by a corruption occurring in another thread.
162 static INLINEinline void compareExchangeHeader(void *Ptr,
163 UnpackedHeader *NewUnpackedHeader,
164 UnpackedHeader *OldUnpackedHeader) {
165 NewUnpackedHeader->Checksum = computeChecksum(Ptr, NewUnpackedHeader);
166 PackedHeader NewPackedHeader = bit_cast<PackedHeader>(*NewUnpackedHeader);
167 PackedHeader OldPackedHeader = bit_cast<PackedHeader>(*OldUnpackedHeader);
168 if (UNLIKELY(!atomic_compare_exchange_strong(__builtin_expect(!!(!atomic_compare_exchange_strong( getAtomicHeader
(Ptr), &OldPackedHeader, NewPackedHeader, memory_order_relaxed
)), 0)
169 getAtomicHeader(Ptr), &OldPackedHeader, NewPackedHeader,__builtin_expect(!!(!atomic_compare_exchange_strong( getAtomicHeader
(Ptr), &OldPackedHeader, NewPackedHeader, memory_order_relaxed
)), 0)
170 memory_order_relaxed))__builtin_expect(!!(!atomic_compare_exchange_strong( getAtomicHeader
(Ptr), &OldPackedHeader, NewPackedHeader, memory_order_relaxed
)), 0)
)
171 dieWithMessage("race on chunk header at address %p\n", Ptr);
172 }
173} // namespace Chunk
174
175struct QuarantineCallback {
176 explicit QuarantineCallback(AllocatorCacheT *Cache)
177 : Cache_(Cache) {}
178
179 // Chunk recycling function, returns a quarantined chunk to the backend,
180 // first making sure it hasn't been tampered with.
181 void Recycle(void *Ptr) {
182 UnpackedHeader Header;
183 Chunk::loadHeader(Ptr, &Header);
184 if (UNLIKELY(Header.State != ChunkQuarantine)__builtin_expect(!!(Header.State != ChunkQuarantine), 0))
185 dieWithMessage("invalid chunk state when recycling address %p\n", Ptr);
186 UnpackedHeader NewHeader = Header;
187 NewHeader.State = ChunkAvailable;
188 Chunk::compareExchangeHeader(Ptr, &NewHeader, &Header);
189 void *BackendPtr = Chunk::getBackendPtr(Ptr, &Header);
190 if (Header.ClassId)
191 getBackend().deallocatePrimary(Cache_, BackendPtr, Header.ClassId);
192 else
193 getBackend().deallocateSecondary(BackendPtr);
194 }
195
196 // Internal quarantine allocation and deallocation functions. We first check
197 // that the batches are indeed serviced by the Primary.
198 // TODO(kostyak): figure out the best way to protect the batches.
199 void *Allocate(uptr Size) {
200 const uptr BatchClassId = SizeClassMap::ClassID(sizeof(QuarantineBatch));
201 return getBackend().allocatePrimary(Cache_, BatchClassId);
202 }
203
204 void Deallocate(void *Ptr) {
205 const uptr BatchClassId = SizeClassMap::ClassID(sizeof(QuarantineBatch));
206 getBackend().deallocatePrimary(Cache_, Ptr, BatchClassId);
207 }
208
209 AllocatorCacheT *Cache_;
210 COMPILER_CHECK(sizeof(QuarantineBatch) < SizeClassMap::kMaxSize)typedef char assertion_failed__210[2*(int)(sizeof(QuarantineBatch
) < SizeClassMap::kMaxSize)-1]
;
211};
212
213typedef Quarantine<QuarantineCallback, void> QuarantineT;
214typedef QuarantineT::Cache QuarantineCacheT;
215COMPILER_CHECK(sizeof(QuarantineCacheT) <=typedef char assertion_failed__216[2*(int)(sizeof(QuarantineCacheT
) <= sizeof(ScudoTSD::QuarantineCachePlaceHolder))-1]
216 sizeof(ScudoTSD::QuarantineCachePlaceHolder))typedef char assertion_failed__216[2*(int)(sizeof(QuarantineCacheT
) <= sizeof(ScudoTSD::QuarantineCachePlaceHolder))-1]
;
217
218QuarantineCacheT *getQuarantineCache(ScudoTSD *TSD) {
219 return reinterpret_cast<QuarantineCacheT *>(TSD->QuarantineCachePlaceHolder);
220}
221
222#ifdef GWP_ASAN_HOOKS1
223static gwp_asan::GuardedPoolAllocator GuardedAlloc;
224#endif // GWP_ASAN_HOOKS
225
226struct Allocator {
227 static const uptr MaxAllowedMallocSize =
228 FIRST_32_SECOND_64(2UL << 30, 1ULL << 40)(2UL << 30);
229
230 BackendT Backend;
231 QuarantineT Quarantine;
232
233 u32 QuarantineChunksUpToSize;
234
235 bool DeallocationTypeMismatch;
236 bool ZeroContents;
237 bool DeleteSizeMismatch;
238
239 bool CheckRssLimit;
240 uptr HardRssLimitMb;
241 uptr SoftRssLimitMb;
242 atomic_uint8_t RssLimitExceeded;
243 atomic_uint64_t RssLastCheckedAtNS;
244
245 explicit Allocator(LinkerInitialized)
246 : Quarantine(LINKER_INITIALIZED) {}
247
248 NOINLINE__attribute__((noinline)) void performSanityChecks();
249
250 void init() {
251 SanitizerToolName = "Scudo";
252 PrimaryAllocatorName = "ScudoPrimary";
253 SecondaryAllocatorName = "ScudoSecondary";
254
255 initFlags();
256
257 performSanityChecks();
258
259 // Check if hardware CRC32 is supported in the binary and by the platform,
260 // if so, opt for the CRC32 hardware version of the checksum.
261 if (&computeHardwareCRC32 && hasHardwareCRC32())
262 atomic_store_relaxed(&HashAlgorithm, CRC32Hardware);
263
264 SetAllocatorMayReturnNull(common_flags()->allocator_may_return_null);
265 Backend.init(common_flags()->allocator_release_to_os_interval_ms);
266 HardRssLimitMb = common_flags()->hard_rss_limit_mb;
267 SoftRssLimitMb = common_flags()->soft_rss_limit_mb;
268 Quarantine.Init(
269 static_cast<uptr>(getFlags()->QuarantineSizeKb) << 10,
270 static_cast<uptr>(getFlags()->ThreadLocalQuarantineSizeKb) << 10);
271 QuarantineChunksUpToSize = (Quarantine.GetCacheSize() == 0) ? 0 :
272 getFlags()->QuarantineChunksUpToSize;
273 DeallocationTypeMismatch = getFlags()->DeallocationTypeMismatch;
274 DeleteSizeMismatch = getFlags()->DeleteSizeMismatch;
275 ZeroContents = getFlags()->ZeroContents;
276
277 if (UNLIKELY(!GetRandom(reinterpret_cast<void *>(&Cookie), sizeof(Cookie),__builtin_expect(!!(!GetRandom(reinterpret_cast<void *>
(&Cookie), sizeof(Cookie), false)), 0)
278 /*blocking=*/false))__builtin_expect(!!(!GetRandom(reinterpret_cast<void *>
(&Cookie), sizeof(Cookie), false)), 0)
) {
279 Cookie = static_cast<u32>((NanoTime() >> 12) ^
280 (reinterpret_cast<uptr>(this) >> 4));
281 }
282
283 CheckRssLimit = HardRssLimitMb || SoftRssLimitMb;
284 if (CheckRssLimit)
285 atomic_store_relaxed(&RssLastCheckedAtNS, MonotonicNanoTime());
286 }
287
288 // Helper function that checks for a valid Scudo chunk. nullptr isn't.
289 bool isValidPointer(const void *Ptr) {
290 initThreadMaybe();
291 if (UNLIKELY(!Ptr)__builtin_expect(!!(!Ptr), 0))
292 return false;
293 if (!Chunk::isAligned(Ptr))
294 return false;
295 return Chunk::isValid(Ptr);
296 }
297
298 NOINLINE__attribute__((noinline)) bool isRssLimitExceeded();
299
300 // Allocates a chunk.
301 void *allocate(uptr Size, uptr Alignment, AllocType Type,
302 bool ForceZeroContents = false) {
303 initThreadMaybe();
304
305#ifdef GWP_ASAN_HOOKS1
306 if (UNLIKELY(GuardedAlloc.shouldSample())__builtin_expect(!!(GuardedAlloc.shouldSample()), 0)) {
6
Taking false branch
307 if (void *Ptr = GuardedAlloc.allocate(Size))
308 return Ptr;
309 }
310#endif // GWP_ASAN_HOOKS
311
312 if (UNLIKELY(Alignment > MaxAlignment)__builtin_expect(!!(Alignment > MaxAlignment), 0)) {
7
Assuming 'Alignment' is <= 'MaxAlignment'
8
Taking false branch
313 if (AllocatorMayReturnNull())
314 return nullptr;
315 reportAllocationAlignmentTooBig(Alignment, MaxAlignment);
316 }
317 if (UNLIKELY(Alignment < MinAlignment)__builtin_expect(!!(Alignment < MinAlignment), 0))
9
Assuming 'Alignment' is >= 'MinAlignment'
10
Taking false branch
318 Alignment = MinAlignment;
319
320 const uptr NeededSize = RoundUpTo(Size
10.1
'Size' is not equal to 0
10.1
'Size' is not equal to 0
10.1
'Size' is not equal to 0
? Size : 1, MinAlignment) +
11
'?' condition is true
321 Chunk::getHeaderSize();
322 const uptr AlignedSize = (Alignment > MinAlignment) ?
12
Assuming 'Alignment' is <= 'MinAlignment'
13
'?' condition is false
323 NeededSize + (Alignment - Chunk::getHeaderSize()) : NeededSize;
324 if (UNLIKELY(Size >= MaxAllowedMallocSize)__builtin_expect(!!(Size >= MaxAllowedMallocSize), 0) ||
15
Taking false branch
325 UNLIKELY(AlignedSize >= MaxAllowedMallocSize)__builtin_expect(!!(AlignedSize >= MaxAllowedMallocSize), 0
)
) {
14
Assuming 'AlignedSize' is < 'MaxAllowedMallocSize'
326 if (AllocatorMayReturnNull())
327 return nullptr;
328 reportAllocationSizeTooBig(Size, AlignedSize, MaxAllowedMallocSize);
329 }
330
331 if (CheckRssLimit && UNLIKELY(isRssLimitExceeded())__builtin_expect(!!(isRssLimitExceeded()), 0)) {
16
Assuming field 'CheckRssLimit' is false
332 if (AllocatorMayReturnNull())
333 return nullptr;
334 reportRssLimitExceeded();
335 }
336
337 // Primary and Secondary backed allocations have a different treatment. We
338 // deal with alignment requirements of Primary serviced allocations here,
339 // but the Secondary will take care of its own alignment needs.
340 void *BackendPtr;
341 uptr BackendSize;
342 u8 ClassId;
343 if (PrimaryT::CanAllocate(AlignedSize, MinAlignment)) {
17
Taking true branch
344 BackendSize = AlignedSize;
345 ClassId = SizeClassMap::ClassID(BackendSize);
346 bool UnlockRequired;
347 ScudoTSD *TSD = getTSDAndLock(&UnlockRequired);
348 BackendPtr = Backend.allocatePrimary(&TSD->Cache, ClassId);
349 if (UnlockRequired
17.1
'UnlockRequired' is false
17.1
'UnlockRequired' is false
17.1
'UnlockRequired' is false
)
18
Taking false branch
350 TSD->unlock();
351 } else {
352 BackendSize = NeededSize;
353 ClassId = 0;
354 BackendPtr = Backend.allocateSecondary(BackendSize, Alignment);
355 }
356 if (UNLIKELY(!BackendPtr)__builtin_expect(!!(!BackendPtr), 0)) {
19
Assuming 'BackendPtr' is non-null
20
Taking false branch
357 SetAllocatorOutOfMemory();
358 if (AllocatorMayReturnNull())
359 return nullptr;
360 reportOutOfMemory(Size);
361 }
362
363 // If requested, we will zero out the entire contents of the returned chunk.
364 if ((ForceZeroContents
20.1
'ForceZeroContents' is false
20.1
'ForceZeroContents' is false
20.1
'ForceZeroContents' is false
|| ZeroContents) && ClassId)
21
Assuming field 'ZeroContents' is true
22
Assuming 'ClassId' is not equal to 0
23
Taking true branch
365 memset(BackendPtr, 0, PrimaryT::ClassIdToSize(ClassId));
24
Calling 'SizeClassAllocator32::ClassIdToSize'
366
367 UnpackedHeader Header = {};
368 uptr UserPtr = reinterpret_cast<uptr>(BackendPtr) + Chunk::getHeaderSize();
369 if (UNLIKELY(!IsAligned(UserPtr, Alignment))__builtin_expect(!!(!IsAligned(UserPtr, Alignment)), 0)) {
370 // Since the Secondary takes care of alignment, a non-aligned pointer
371 // means it is from the Primary. It is also the only case where the offset
372 // field of the header would be non-zero.
373 DCHECK(ClassId);
374 const uptr AlignedUserPtr = RoundUpTo(UserPtr, Alignment);
375 Header.Offset = (AlignedUserPtr - UserPtr) >> MinAlignmentLog;
376 UserPtr = AlignedUserPtr;
377 }
378 DCHECK_LE(UserPtr + Size, reinterpret_cast<uptr>(BackendPtr) + BackendSize);
379 Header.State = ChunkAllocated;
380 Header.AllocType = Type;
381 if (ClassId) {
382 Header.ClassId = ClassId;
383 Header.SizeOrUnusedBytes = Size;
384 } else {
385 // The secondary fits the allocations to a page, so the amount of unused
386 // bytes is the difference between the end of the user allocation and the
387 // next page boundary.
388 const uptr PageSize = GetPageSizeCached();
389 const uptr TrailingBytes = (UserPtr + Size) & (PageSize - 1);
390 if (TrailingBytes)
391 Header.SizeOrUnusedBytes = PageSize - TrailingBytes;
392 }
393 void *Ptr = reinterpret_cast<void *>(UserPtr);
394 Chunk::storeHeader(Ptr, &Header);
395 if (SCUDO_CAN_USE_HOOKS0 && &__sanitizer_malloc_hook)
396 __sanitizer_malloc_hook(Ptr, Size);
397 return Ptr;
398 }
399
400 // Place a chunk in the quarantine or directly deallocate it in the event of
401 // a zero-sized quarantine, or if the size of the chunk is greater than the
402 // quarantine chunk size threshold.
403 void quarantineOrDeallocateChunk(void *Ptr, UnpackedHeader *Header,
404 uptr Size) {
405 const bool BypassQuarantine = !Size || (Size > QuarantineChunksUpToSize);
406 if (BypassQuarantine) {
407 UnpackedHeader NewHeader = *Header;
408 NewHeader.State = ChunkAvailable;
409 Chunk::compareExchangeHeader(Ptr, &NewHeader, Header);
410 void *BackendPtr = Chunk::getBackendPtr(Ptr, Header);
411 if (Header->ClassId) {
412 bool UnlockRequired;
413 ScudoTSD *TSD = getTSDAndLock(&UnlockRequired);
414 getBackend().deallocatePrimary(&TSD->Cache, BackendPtr,
415 Header->ClassId);
416 if (UnlockRequired)
417 TSD->unlock();
418 } else {
419 getBackend().deallocateSecondary(BackendPtr);
420 }
421 } else {
422 // If a small memory amount was allocated with a larger alignment, we want
423 // to take that into account. Otherwise the Quarantine would be filled
424 // with tiny chunks, taking a lot of VA memory. This is an approximation
425 // of the usable size, that allows us to not call
426 // GetActuallyAllocatedSize.
427 const uptr EstimatedSize = Size + (Header->Offset << MinAlignmentLog);
428 UnpackedHeader NewHeader = *Header;
429 NewHeader.State = ChunkQuarantine;
430 Chunk::compareExchangeHeader(Ptr, &NewHeader, Header);
431 bool UnlockRequired;
432 ScudoTSD *TSD = getTSDAndLock(&UnlockRequired);
433 Quarantine.Put(getQuarantineCache(TSD), QuarantineCallback(&TSD->Cache),
434 Ptr, EstimatedSize);
435 if (UnlockRequired)
436 TSD->unlock();
437 }
438 }
439
440 // Deallocates a Chunk, which means either adding it to the quarantine or
441 // directly returning it to the backend if criteria are met.
442 void deallocate(void *Ptr, uptr DeleteSize, uptr DeleteAlignment,
443 AllocType Type) {
444 // For a deallocation, we only ensure minimal initialization, meaning thread
445 // local data will be left uninitialized for now (when using ELF TLS). The
446 // fallback cache will be used instead. This is a workaround for a situation
447 // where the only heap operation performed in a thread would be a free past
448 // the TLS destructors, ending up in initialized thread specific data never
449 // being destroyed properly. Any other heap operation will do a full init.
450 initThreadMaybe(/*MinimalInit=*/true);
451 if (SCUDO_CAN_USE_HOOKS0 && &__sanitizer_free_hook)
452 __sanitizer_free_hook(Ptr);
453 if (UNLIKELY(!Ptr)__builtin_expect(!!(!Ptr), 0))
454 return;
455
456#ifdef GWP_ASAN_HOOKS1
457 if (UNLIKELY(GuardedAlloc.pointerIsMine(Ptr))__builtin_expect(!!(GuardedAlloc.pointerIsMine(Ptr)), 0)) {
458 GuardedAlloc.deallocate(Ptr);
459 return;
460 }
461#endif // GWP_ASAN_HOOKS
462
463 if (UNLIKELY(!Chunk::isAligned(Ptr))__builtin_expect(!!(!Chunk::isAligned(Ptr)), 0))
464 dieWithMessage("misaligned pointer when deallocating address %p\n", Ptr);
465 UnpackedHeader Header;
466 Chunk::loadHeader(Ptr, &Header);
467 if (UNLIKELY(Header.State != ChunkAllocated)__builtin_expect(!!(Header.State != ChunkAllocated), 0))
468 dieWithMessage("invalid chunk state when deallocating address %p\n", Ptr);
469 if (DeallocationTypeMismatch) {
470 // The deallocation type has to match the allocation one.
471 if (Header.AllocType != Type) {
472 // With the exception of memalign'd Chunks, that can be still be free'd.
473 if (Header.AllocType != FromMemalign || Type != FromMalloc)
474 dieWithMessage("allocation type mismatch when deallocating address "
475 "%p\n", Ptr);
476 }
477 }
478 const uptr Size = Chunk::getSize(Ptr, &Header);
479 if (DeleteSizeMismatch) {
480 if (DeleteSize && DeleteSize != Size)
481 dieWithMessage("invalid sized delete when deallocating address %p\n",
482 Ptr);
483 }
484 (void)DeleteAlignment; // TODO(kostyak): verify that the alignment matches.
485 quarantineOrDeallocateChunk(Ptr, &Header, Size);
486 }
487
488 // Reallocates a chunk. We can save on a new allocation if the new requested
489 // size still fits in the chunk.
490 void *reallocate(void *OldPtr, uptr NewSize) {
491 initThreadMaybe();
492
493#ifdef GWP_ASAN_HOOKS1
494 if (UNLIKELY(GuardedAlloc.pointerIsMine(OldPtr))__builtin_expect(!!(GuardedAlloc.pointerIsMine(OldPtr)), 0)) {
495 size_t OldSize = GuardedAlloc.getSize(OldPtr);
496 void *NewPtr = allocate(NewSize, MinAlignment, FromMalloc);
497 if (NewPtr)
498 memcpy(NewPtr, OldPtr, (NewSize < OldSize) ? NewSize : OldSize);
499 GuardedAlloc.deallocate(OldPtr);
500 return NewPtr;
501 }
502#endif // GWP_ASAN_HOOKS
503
504 if (UNLIKELY(!Chunk::isAligned(OldPtr))__builtin_expect(!!(!Chunk::isAligned(OldPtr)), 0))
505 dieWithMessage("misaligned address when reallocating address %p\n",
506 OldPtr);
507 UnpackedHeader OldHeader;
508 Chunk::loadHeader(OldPtr, &OldHeader);
509 if (UNLIKELY(OldHeader.State != ChunkAllocated)__builtin_expect(!!(OldHeader.State != ChunkAllocated), 0))
510 dieWithMessage("invalid chunk state when reallocating address %p\n",
511 OldPtr);
512 if (DeallocationTypeMismatch) {
513 if (UNLIKELY(OldHeader.AllocType != FromMalloc)__builtin_expect(!!(OldHeader.AllocType != FromMalloc), 0))
514 dieWithMessage("allocation type mismatch when reallocating address "
515 "%p\n", OldPtr);
516 }
517 const uptr UsableSize = Chunk::getUsableSize(OldPtr, &OldHeader);
518 // The new size still fits in the current chunk, and the size difference
519 // is reasonable.
520 if (NewSize <= UsableSize &&
521 (UsableSize - NewSize) < (SizeClassMap::kMaxSize / 2)) {
522 UnpackedHeader NewHeader = OldHeader;
523 NewHeader.SizeOrUnusedBytes =
524 OldHeader.ClassId ? NewSize : UsableSize - NewSize;
525 Chunk::compareExchangeHeader(OldPtr, &NewHeader, &OldHeader);
526 return OldPtr;
527 }
528 // Otherwise, we have to allocate a new chunk and copy the contents of the
529 // old one.
530 void *NewPtr = allocate(NewSize, MinAlignment, FromMalloc);
531 if (NewPtr) {
532 const uptr OldSize = OldHeader.ClassId ? OldHeader.SizeOrUnusedBytes :
533 UsableSize - OldHeader.SizeOrUnusedBytes;
534 memcpy(NewPtr, OldPtr, Min(NewSize, UsableSize));
535 quarantineOrDeallocateChunk(OldPtr, &OldHeader, OldSize);
536 }
537 return NewPtr;
538 }
539
540 // Helper function that returns the actual usable size of a chunk.
541 uptr getUsableSize(const void *Ptr) {
542 initThreadMaybe();
543 if (UNLIKELY(!Ptr)__builtin_expect(!!(!Ptr), 0))
544 return 0;
545
546#ifdef GWP_ASAN_HOOKS1
547 if (UNLIKELY(GuardedAlloc.pointerIsMine(Ptr))__builtin_expect(!!(GuardedAlloc.pointerIsMine(Ptr)), 0))
548 return GuardedAlloc.getSize(Ptr);
549#endif // GWP_ASAN_HOOKS
550
551 UnpackedHeader Header;
552 Chunk::loadHeader(Ptr, &Header);
553 // Getting the usable size of a chunk only makes sense if it's allocated.
554 if (UNLIKELY(Header.State != ChunkAllocated)__builtin_expect(!!(Header.State != ChunkAllocated), 0))
555 dieWithMessage("invalid chunk state when sizing address %p\n", Ptr);
556 return Chunk::getUsableSize(Ptr, &Header);
557 }
558
559 void *calloc(uptr NMemB, uptr Size) {
560 initThreadMaybe();
561 if (UNLIKELY(CheckForCallocOverflow(NMemB, Size))__builtin_expect(!!(CheckForCallocOverflow(NMemB, Size)), 0)) {
562 if (AllocatorMayReturnNull())
563 return nullptr;
564 reportCallocOverflow(NMemB, Size);
565 }
566 return allocate(NMemB * Size, MinAlignment, FromMalloc, true);
567 }
568
569 void commitBack(ScudoTSD *TSD) {
570 Quarantine.Drain(getQuarantineCache(TSD), QuarantineCallback(&TSD->Cache));
571 Backend.destroyCache(&TSD->Cache);
572 }
573
574 uptr getStats(AllocatorStat StatType) {
575 initThreadMaybe();
576 uptr stats[AllocatorStatCount];
577 Backend.getStats(stats);
578 return stats[StatType];
579 }
580
581 bool canReturnNull() {
582 initThreadMaybe();
583 return AllocatorMayReturnNull();
584 }
585
586 void setRssLimit(uptr LimitMb, bool HardLimit) {
587 if (HardLimit)
588 HardRssLimitMb = LimitMb;
589 else
590 SoftRssLimitMb = LimitMb;
591 CheckRssLimit = HardRssLimitMb || SoftRssLimitMb;
592 }
593
594 void printStats() {
595 initThreadMaybe();
596 Backend.printStats();
597 }
598};
599
600NOINLINE__attribute__((noinline)) void Allocator::performSanityChecks() {
601 // Verify that the header offset field can hold the maximum offset. In the
602 // case of the Secondary allocator, it takes care of alignment and the
603 // offset will always be 0. In the case of the Primary, the worst case
604 // scenario happens in the last size class, when the backend allocation
605 // would already be aligned on the requested alignment, which would happen
606 // to be the maximum alignment that would fit in that size class. As a
607 // result, the maximum offset will be at most the maximum alignment for the
608 // last size class minus the header size, in multiples of MinAlignment.
609 UnpackedHeader Header = {};
610 const uptr MaxPrimaryAlignment =
611 1 << MostSignificantSetBitIndex(SizeClassMap::kMaxSize - MinAlignment);
612 const uptr MaxOffset =
613 (MaxPrimaryAlignment - Chunk::getHeaderSize()) >> MinAlignmentLog;
614 Header.Offset = MaxOffset;
615 if (Header.Offset != MaxOffset)
616 dieWithMessage("maximum possible offset doesn't fit in header\n");
617 // Verify that we can fit the maximum size or amount of unused bytes in the
618 // header. Given that the Secondary fits the allocation to a page, the worst
619 // case scenario happens in the Primary. It will depend on the second to
620 // last and last class sizes, as well as the dynamic base for the Primary.
621 // The following is an over-approximation that works for our needs.
622 const uptr MaxSizeOrUnusedBytes = SizeClassMap::kMaxSize - 1;
623 Header.SizeOrUnusedBytes = MaxSizeOrUnusedBytes;
624 if (Header.SizeOrUnusedBytes != MaxSizeOrUnusedBytes)
625 dieWithMessage("maximum possible unused bytes doesn't fit in header\n");
626
627 const uptr LargestClassId = SizeClassMap::kLargestClassID;
628 Header.ClassId = LargestClassId;
629 if (Header.ClassId != LargestClassId)
630 dieWithMessage("largest class ID doesn't fit in header\n");
631}
632
633// Opportunistic RSS limit check. This will update the RSS limit status, if
634// it can, every 250ms, otherwise it will just return the current one.
635NOINLINE__attribute__((noinline)) bool Allocator::isRssLimitExceeded() {
636 u64 LastCheck = atomic_load_relaxed(&RssLastCheckedAtNS);
637 const u64 CurrentCheck = MonotonicNanoTime();
638 if (LIKELY(CurrentCheck < LastCheck + (250ULL * 1000000ULL))__builtin_expect(!!(CurrentCheck < LastCheck + (250ULL * 1000000ULL
)), 1)
)
639 return atomic_load_relaxed(&RssLimitExceeded);
640 if (!atomic_compare_exchange_weak(&RssLastCheckedAtNS, &LastCheck,
641 CurrentCheck, memory_order_relaxed))
642 return atomic_load_relaxed(&RssLimitExceeded);
643 // TODO(kostyak): We currently use sanitizer_common's GetRSS which reads the
644 // RSS from /proc/self/statm by default. We might want to
645 // call getrusage directly, even if it's less accurate.
646 const uptr CurrentRssMb = GetRSS() >> 20;
647 if (HardRssLimitMb && UNLIKELY(HardRssLimitMb < CurrentRssMb)__builtin_expect(!!(HardRssLimitMb < CurrentRssMb), 0))
648 dieWithMessage("hard RSS limit exhausted (%zdMb vs %zdMb)\n",
649 HardRssLimitMb, CurrentRssMb);
650 if (SoftRssLimitMb) {
651 if (atomic_load_relaxed(&RssLimitExceeded)) {
652 if (CurrentRssMb <= SoftRssLimitMb)
653 atomic_store_relaxed(&RssLimitExceeded, false);
654 } else {
655 if (CurrentRssMb > SoftRssLimitMb) {
656 atomic_store_relaxed(&RssLimitExceeded, true);
657 Printf("Scudo INFO: soft RSS limit exhausted (%zdMb vs %zdMb)\n",
658 SoftRssLimitMb, CurrentRssMb);
659 }
660 }
661 }
662 return atomic_load_relaxed(&RssLimitExceeded);
663}
664
665static Allocator Instance(LINKER_INITIALIZED);
666
667static BackendT &getBackend() {
668 return Instance.Backend;
669}
670
671void initScudo() {
672 Instance.init();
673#ifdef GWP_ASAN_HOOKS1
674 gwp_asan::options::initOptions();
675 gwp_asan::options::Options &Opts = gwp_asan::options::getOptions();
676 Opts.Backtrace = gwp_asan::options::getBacktraceFunction();
677 Opts.PrintBacktrace = gwp_asan::options::getPrintBacktraceFunction();
678 GuardedAlloc.init(Opts);
679#endif // GWP_ASAN_HOOKS
680}
681
682void ScudoTSD::init() {
683 getBackend().initCache(&Cache);
684 memset(QuarantineCachePlaceHolder, 0, sizeof(QuarantineCachePlaceHolder));
685}
686
687void ScudoTSD::commitBack() {
688 Instance.commitBack(this);
689}
690
691void *scudoAllocate(uptr Size, uptr Alignment, AllocType Type) {
692 if (Alignment && UNLIKELY(!IsPowerOfTwo(Alignment))__builtin_expect(!!(!IsPowerOfTwo(Alignment)), 0)) {
693 errno(*__errno_location ()) = EINVAL22;
694 if (Instance.canReturnNull())
695 return nullptr;
696 reportAllocationAlignmentNotPowerOfTwo(Alignment);
697 }
698 return SetErrnoOnNull(Instance.allocate(Size, Alignment, Type));
699}
700
701void scudoDeallocate(void *Ptr, uptr Size, uptr Alignment, AllocType Type) {
702 Instance.deallocate(Ptr, Size, Alignment, Type);
703}
704
705void *scudoRealloc(void *Ptr, uptr Size) {
706 if (!Ptr)
707 return SetErrnoOnNull(Instance.allocate(Size, MinAlignment, FromMalloc));
708 if (Size == 0) {
709 Instance.deallocate(Ptr, 0, 0, FromMalloc);
710 return nullptr;
711 }
712 return SetErrnoOnNull(Instance.reallocate(Ptr, Size));
713}
714
715void *scudoCalloc(uptr NMemB, uptr Size) {
716 return SetErrnoOnNull(Instance.calloc(NMemB, Size));
717}
718
719void *scudoValloc(uptr Size) {
720 return SetErrnoOnNull(
721 Instance.allocate(Size, GetPageSizeCached(), FromMemalign));
722}
723
724void *scudoPvalloc(uptr Size) {
725 const uptr PageSize = GetPageSizeCached();
726 if (UNLIKELY(CheckForPvallocOverflow(Size, PageSize))__builtin_expect(!!(CheckForPvallocOverflow(Size, PageSize)),
0)
) {
1
Assuming the condition is false
2
Taking false branch
727 errno(*__errno_location ()) = ENOMEM12;
728 if (Instance.canReturnNull())
729 return nullptr;
730 reportPvallocOverflow(Size);
731 }
732 // pvalloc(0) should allocate one page.
733 Size = Size ? RoundUpTo(Size, PageSize) : PageSize;
3
Assuming 'Size' is 0
4
'?' condition is false
734 return SetErrnoOnNull(Instance.allocate(Size, PageSize, FromMemalign));
5
Calling 'Allocator::allocate'
735}
736
737int scudoPosixMemalign(void **MemPtr, uptr Alignment, uptr Size) {
738 if (UNLIKELY(!CheckPosixMemalignAlignment(Alignment))__builtin_expect(!!(!CheckPosixMemalignAlignment(Alignment)),
0)
) {
739 if (!Instance.canReturnNull())
740 reportInvalidPosixMemalignAlignment(Alignment);
741 return EINVAL22;
742 }
743 void *Ptr = Instance.allocate(Size, Alignment, FromMemalign);
744 if (UNLIKELY(!Ptr)__builtin_expect(!!(!Ptr), 0))
745 return ENOMEM12;
746 *MemPtr = Ptr;
747 return 0;
748}
749
750void *scudoAlignedAlloc(uptr Alignment, uptr Size) {
751 if (UNLIKELY(!CheckAlignedAllocAlignmentAndSize(Alignment, Size))__builtin_expect(!!(!CheckAlignedAllocAlignmentAndSize(Alignment
, Size)), 0)
) {
752 errno(*__errno_location ()) = EINVAL22;
753 if (Instance.canReturnNull())
754 return nullptr;
755 reportInvalidAlignedAllocAlignment(Size, Alignment);
756 }
757 return SetErrnoOnNull(Instance.allocate(Size, Alignment, FromMalloc));
758}
759
760uptr scudoMallocUsableSize(void *Ptr) {
761 return Instance.getUsableSize(Ptr);
762}
763
764} // namespace __scudo
765
766using namespace __scudo;
767
768// MallocExtension helper functions
769
770uptr __sanitizer_get_current_allocated_bytes() {
771 return Instance.getStats(AllocatorStatAllocated);
772}
773
774uptr __sanitizer_get_heap_size() {
775 return Instance.getStats(AllocatorStatMapped);
776}
777
778uptr __sanitizer_get_free_bytes() {
779 return 1;
780}
781
782uptr __sanitizer_get_unmapped_bytes() {
783 return 1;
784}
785
786uptr __sanitizer_get_estimated_allocated_size(uptr Size) {
787 return Size;
788}
789
790int __sanitizer_get_ownership(const void *Ptr) {
791 return Instance.isValidPointer(Ptr);
792}
793
794uptr __sanitizer_get_allocated_size(const void *Ptr) {
795 return Instance.getUsableSize(Ptr);
796}
797
798#if !SANITIZER_SUPPORTS_WEAK_HOOKS1
799SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_malloc_hook,extern "C" __attribute__((visibility("default"))) __attribute__
((weak)) void __sanitizer_malloc_hook(void *Ptr, uptr Size)
800 void *Ptr, uptr Size)extern "C" __attribute__((visibility("default"))) __attribute__
((weak)) void __sanitizer_malloc_hook(void *Ptr, uptr Size)
{
801 (void)Ptr;
802 (void)Size;
803}
804
805SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_free_hook, void *Ptr)extern "C" __attribute__((visibility("default"))) __attribute__
((weak)) void __sanitizer_free_hook(void *Ptr)
{
806 (void)Ptr;
807}
808#endif
809
810// Interface functions
811
812void __scudo_set_rss_limit(uptr LimitMb, s32 HardLimit) {
813 if (!SCUDO_CAN_USE_PUBLIC_INTERFACE1)
814 return;
815 Instance.setRssLimit(LimitMb, !!HardLimit);
816}
817
818void __scudo_print_stats() {
819 Instance.printStats();
820}

/build/llvm-toolchain-snapshot-10~svn374877/projects/compiler-rt/lib/scudo/../sanitizer_common/sanitizer_allocator_primary32.h

1//===-- sanitizer_allocator_primary32.h -------------------------*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// Part of the Sanitizer Allocator.
10//
11//===----------------------------------------------------------------------===//
12#ifndef SANITIZER_ALLOCATOR_H
13#error This file must be included inside sanitizer_allocator.h
14#endif
15
16template<class SizeClassAllocator> struct SizeClassAllocator32LocalCache;
17
18// SizeClassAllocator32 -- allocator for 32-bit address space.
19// This allocator can theoretically be used on 64-bit arch, but there it is less
20// efficient than SizeClassAllocator64.
21//
22// [kSpaceBeg, kSpaceBeg + kSpaceSize) is the range of addresses which can
23// be returned by MmapOrDie().
24//
25// Region:
26// a result of a single call to MmapAlignedOrDieOnFatalError(kRegionSize,
27// kRegionSize).
28// Since the regions are aligned by kRegionSize, there are exactly
29// kNumPossibleRegions possible regions in the address space and so we keep
30// a ByteMap possible_regions to store the size classes of each Region.
31// 0 size class means the region is not used by the allocator.
32//
33// One Region is used to allocate chunks of a single size class.
34// A Region looks like this:
35// UserChunk1 .. UserChunkN <gap> MetaChunkN .. MetaChunk1
36//
37// In order to avoid false sharing the objects of this class should be
38// chache-line aligned.
39
40struct SizeClassAllocator32FlagMasks { // Bit masks.
41 enum {
42 kRandomShuffleChunks = 1,
43 kUseSeparateSizeClassForBatch = 2,
44 };
45};
46
47template <class Params>
48class SizeClassAllocator32 {
49 private:
50 static const u64 kTwoLevelByteMapSize1 =
51 (Params::kSpaceSize >> Params::kRegionSizeLog) >> 12;
52 static const u64 kMinFirstMapSizeTwoLevelByteMap = 4;
53
54 public:
55 using AddressSpaceView = typename Params::AddressSpaceView;
56 static const uptr kSpaceBeg = Params::kSpaceBeg;
57 static const u64 kSpaceSize = Params::kSpaceSize;
58 static const uptr kMetadataSize = Params::kMetadataSize;
59 typedef typename Params::SizeClassMap SizeClassMap;
60 static const uptr kRegionSizeLog = Params::kRegionSizeLog;
61 typedef typename Params::MapUnmapCallback MapUnmapCallback;
62 using ByteMap = typename conditional<
63 (kTwoLevelByteMapSize1 < kMinFirstMapSizeTwoLevelByteMap),
64 FlatByteMap<(Params::kSpaceSize >> Params::kRegionSizeLog),
65 AddressSpaceView>,
66 TwoLevelByteMap<kTwoLevelByteMapSize1, 1 << 12, AddressSpaceView>>::type;
67
68 COMPILER_CHECK(!SANITIZER_SIGN_EXTENDED_ADDRESSES ||typedef char assertion_failed__69[2*(int)(!0 || (kSpaceSize &
(kSpaceSize - 1)) == 0)-1]
69 (kSpaceSize & (kSpaceSize - 1)) == 0)typedef char assertion_failed__69[2*(int)(!0 || (kSpaceSize &
(kSpaceSize - 1)) == 0)-1]
;
70
71 static const bool kRandomShuffleChunks = Params::kFlags &
72 SizeClassAllocator32FlagMasks::kRandomShuffleChunks;
73 static const bool kUseSeparateSizeClassForBatch = Params::kFlags &
74 SizeClassAllocator32FlagMasks::kUseSeparateSizeClassForBatch;
75
76 struct TransferBatch {
77 static const uptr kMaxNumCached = SizeClassMap::kMaxNumCachedHint - 2;
78 void SetFromArray(void *batch[], uptr count) {
79 DCHECK_LE(count, kMaxNumCached);
80 count_ = count;
81 for (uptr i = 0; i < count; i++)
82 batch_[i] = batch[i];
83 }
84 uptr Count() const { return count_; }
85 void Clear() { count_ = 0; }
86 void Add(void *ptr) {
87 batch_[count_++] = ptr;
88 DCHECK_LE(count_, kMaxNumCached);
89 }
90 void CopyToArray(void *to_batch[]) const {
91 for (uptr i = 0, n = Count(); i < n; i++)
92 to_batch[i] = batch_[i];
93 }
94
95 // How much memory do we need for a batch containing n elements.
96 static uptr AllocationSizeRequiredForNElements(uptr n) {
97 return sizeof(uptr) * 2 + sizeof(void *) * n;
98 }
99 static uptr MaxCached(uptr size) {
100 return Min(kMaxNumCached, SizeClassMap::MaxCachedHint(size));
101 }
102
103 TransferBatch *next;
104
105 private:
106 uptr count_;
107 void *batch_[kMaxNumCached];
108 };
109
110 static const uptr kBatchSize = sizeof(TransferBatch);
111 COMPILER_CHECK((kBatchSize & (kBatchSize - 1)) == 0)typedef char assertion_failed__111[2*(int)((kBatchSize & (
kBatchSize - 1)) == 0)-1]
;
112 COMPILER_CHECK(kBatchSize == SizeClassMap::kMaxNumCachedHint * sizeof(uptr))typedef char assertion_failed__112[2*(int)(kBatchSize == SizeClassMap
::kMaxNumCachedHint * sizeof(uptr))-1]
;
113
114 static uptr ClassIdToSize(uptr class_id) {
115 return (class_id == SizeClassMap::kBatchClassID) ?
25
Assuming 'class_id' is not equal to 'kBatchClassID'
26
'?' condition is false
116 kBatchSize : SizeClassMap::Size(class_id);
27
Calling 'SizeClassMap::Size'
117 }
118
119 typedef SizeClassAllocator32<Params> ThisT;
120 typedef SizeClassAllocator32LocalCache<ThisT> AllocatorCache;
121
122 void Init(s32 release_to_os_interval_ms) {
123 possible_regions.Init();
124 internal_memset(size_class_info_array, 0, sizeof(size_class_info_array));
125 }
126
127 s32 ReleaseToOSIntervalMs() const {
128 return kReleaseToOSIntervalNever;
129 }
130
131 void SetReleaseToOSIntervalMs(s32 release_to_os_interval_ms) {
132 // This is empty here. Currently only implemented in 64-bit allocator.
133 }
134
135 void ForceReleaseToOS() {
136 // Currently implemented in 64-bit allocator only.
137 }
138
139 void *MapWithCallback(uptr size) {
140 void *res = MmapOrDie(size, PrimaryAllocatorName);
141 MapUnmapCallback().OnMap((uptr)res, size);
142 return res;
143 }
144
145 void UnmapWithCallback(uptr beg, uptr size) {
146 MapUnmapCallback().OnUnmap(beg, size);
147 UnmapOrDie(reinterpret_cast<void *>(beg), size);
148 }
149
150 static bool CanAllocate(uptr size, uptr alignment) {
151 return size <= SizeClassMap::kMaxSize &&
152 alignment <= SizeClassMap::kMaxSize;
153 }
154
155 void *GetMetaData(const void *p) {
156 CHECK(PointerIsMine(p))do { __sanitizer::u64 v1 = (__sanitizer::u64)((PointerIsMine(
p))); __sanitizer::u64 v2 = (__sanitizer::u64)(0); if (__builtin_expect
(!!(!(v1 != v2)), 0)) __sanitizer::CheckFailed("/build/llvm-toolchain-snapshot-10~svn374877/projects/compiler-rt/lib/scudo/../sanitizer_common/sanitizer_allocator_primary32.h"
, 156, "(" "(PointerIsMine(p))" ") " "!=" " (" "0" ")", v1, v2
); } while (false)
;
157 uptr mem = reinterpret_cast<uptr>(p);
158 uptr beg = ComputeRegionBeg(mem);
159 uptr size = ClassIdToSize(GetSizeClass(p));
160 u32 offset = mem - beg;
161 uptr n = offset / (u32)size; // 32-bit division
162 uptr meta = (beg + kRegionSize) - (n + 1) * kMetadataSize;
163 return reinterpret_cast<void*>(meta);
164 }
165
166 NOINLINE__attribute__((noinline)) TransferBatch *AllocateBatch(AllocatorStats *stat, AllocatorCache *c,
167 uptr class_id) {
168 DCHECK_LT(class_id, kNumClasses);
169 SizeClassInfo *sci = GetSizeClassInfo(class_id);
170 SpinMutexLock l(&sci->mutex);
171 if (sci->free_list.empty()) {
172 if (UNLIKELY(!PopulateFreeList(stat, c, sci, class_id))__builtin_expect(!!(!PopulateFreeList(stat, c, sci, class_id)
), 0)
)
173 return nullptr;
174 DCHECK(!sci->free_list.empty());
175 }
176 TransferBatch *b = sci->free_list.front();
177 sci->free_list.pop_front();
178 return b;
179 }
180
181 NOINLINE__attribute__((noinline)) void DeallocateBatch(AllocatorStats *stat, uptr class_id,
182 TransferBatch *b) {
183 DCHECK_LT(class_id, kNumClasses);
184 CHECK_GT(b->Count(), 0)do { __sanitizer::u64 v1 = (__sanitizer::u64)((b->Count())
); __sanitizer::u64 v2 = (__sanitizer::u64)((0)); if (__builtin_expect
(!!(!(v1 > v2)), 0)) __sanitizer::CheckFailed("/build/llvm-toolchain-snapshot-10~svn374877/projects/compiler-rt/lib/scudo/../sanitizer_common/sanitizer_allocator_primary32.h"
, 184, "(" "(b->Count())" ") " ">" " (" "(0)" ")", v1, v2
); } while (false)
;
185 SizeClassInfo *sci = GetSizeClassInfo(class_id);
186 SpinMutexLock l(&sci->mutex);
187 sci->free_list.push_front(b);
188 }
189
190 bool PointerIsMine(const void *p) {
191 uptr mem = reinterpret_cast<uptr>(p);
192 if (SANITIZER_SIGN_EXTENDED_ADDRESSES0)
193 mem &= (kSpaceSize - 1);
194 if (mem < kSpaceBeg || mem >= kSpaceBeg + kSpaceSize)
195 return false;
196 return GetSizeClass(p) != 0;
197 }
198
199 uptr GetSizeClass(const void *p) {
200 return possible_regions[ComputeRegionId(reinterpret_cast<uptr>(p))];
201 }
202
203 void *GetBlockBegin(const void *p) {
204 CHECK(PointerIsMine(p))do { __sanitizer::u64 v1 = (__sanitizer::u64)((PointerIsMine(
p))); __sanitizer::u64 v2 = (__sanitizer::u64)(0); if (__builtin_expect
(!!(!(v1 != v2)), 0)) __sanitizer::CheckFailed("/build/llvm-toolchain-snapshot-10~svn374877/projects/compiler-rt/lib/scudo/../sanitizer_common/sanitizer_allocator_primary32.h"
, 204, "(" "(PointerIsMine(p))" ") " "!=" " (" "0" ")", v1, v2
); } while (false)
;
205 uptr mem = reinterpret_cast<uptr>(p);
206 uptr beg = ComputeRegionBeg(mem);
207 uptr size = ClassIdToSize(GetSizeClass(p));
208 u32 offset = mem - beg;
209 u32 n = offset / (u32)size; // 32-bit division
210 uptr res = beg + (n * (u32)size);
211 return reinterpret_cast<void*>(res);
212 }
213
214 uptr GetActuallyAllocatedSize(void *p) {
215 CHECK(PointerIsMine(p))do { __sanitizer::u64 v1 = (__sanitizer::u64)((PointerIsMine(
p))); __sanitizer::u64 v2 = (__sanitizer::u64)(0); if (__builtin_expect
(!!(!(v1 != v2)), 0)) __sanitizer::CheckFailed("/build/llvm-toolchain-snapshot-10~svn374877/projects/compiler-rt/lib/scudo/../sanitizer_common/sanitizer_allocator_primary32.h"
, 215, "(" "(PointerIsMine(p))" ") " "!=" " (" "0" ")", v1, v2
); } while (false)
;
216 return ClassIdToSize(GetSizeClass(p));
217 }
218
219 static uptr ClassID(uptr size) { return SizeClassMap::ClassID(size); }
220
221 uptr TotalMemoryUsed() {
222 // No need to lock here.
223 uptr res = 0;
224 for (uptr i = 0; i < kNumPossibleRegions; i++)
225 if (possible_regions[i])
226 res += kRegionSize;
227 return res;
228 }
229
230 void TestOnlyUnmap() {
231 for (uptr i = 0; i < kNumPossibleRegions; i++)
232 if (possible_regions[i])
233 UnmapWithCallback((i * kRegionSize), kRegionSize);
234 }
235
236 // ForceLock() and ForceUnlock() are needed to implement Darwin malloc zone
237 // introspection API.
238 void ForceLock() {
239 for (uptr i = 0; i < kNumClasses; i++) {
240 GetSizeClassInfo(i)->mutex.Lock();
241 }
242 }
243
244 void ForceUnlock() {
245 for (int i = kNumClasses - 1; i >= 0; i--) {
246 GetSizeClassInfo(i)->mutex.Unlock();
247 }
248 }
249
250 // Iterate over all existing chunks.
251 // The allocator must be locked when calling this function.
252 void ForEachChunk(ForEachChunkCallback callback, void *arg) {
253 for (uptr region = 0; region < kNumPossibleRegions; region++)
254 if (possible_regions[region]) {
255 uptr chunk_size = ClassIdToSize(possible_regions[region]);
256 uptr max_chunks_in_region = kRegionSize / (chunk_size + kMetadataSize);
257 uptr region_beg = region * kRegionSize;
258 for (uptr chunk = region_beg;
259 chunk < region_beg + max_chunks_in_region * chunk_size;
260 chunk += chunk_size) {
261 // Too slow: CHECK_EQ((void *)chunk, GetBlockBegin((void *)chunk));
262 callback(chunk, arg);
263 }
264 }
265 }
266
267 void PrintStats() {}
268
269 static uptr AdditionalSize() { return 0; }
270
271 typedef SizeClassMap SizeClassMapT;
272 static const uptr kNumClasses = SizeClassMap::kNumClasses;
273
274 private:
275 static const uptr kRegionSize = 1 << kRegionSizeLog;
276 static const uptr kNumPossibleRegions = kSpaceSize / kRegionSize;
277
278 struct ALIGNED(SANITIZER_CACHE_LINE_SIZE)__attribute__((aligned(64))) SizeClassInfo {
279 StaticSpinMutex mutex;
280 IntrusiveList<TransferBatch> free_list;
281 u32 rand_state;
282 };
283 COMPILER_CHECK(sizeof(SizeClassInfo) % kCacheLineSize == 0)typedef char assertion_failed__283[2*(int)(sizeof(SizeClassInfo
) % kCacheLineSize == 0)-1]
;
284
285 uptr ComputeRegionId(uptr mem) const {
286 if (SANITIZER_SIGN_EXTENDED_ADDRESSES0)
287 mem &= (kSpaceSize - 1);
288 const uptr res = mem >> kRegionSizeLog;
289 CHECK_LT(res, kNumPossibleRegions)do { __sanitizer::u64 v1 = (__sanitizer::u64)((res)); __sanitizer
::u64 v2 = (__sanitizer::u64)((kNumPossibleRegions)); if (__builtin_expect
(!!(!(v1 < v2)), 0)) __sanitizer::CheckFailed("/build/llvm-toolchain-snapshot-10~svn374877/projects/compiler-rt/lib/scudo/../sanitizer_common/sanitizer_allocator_primary32.h"
, 289, "(" "(res)" ") " "<" " (" "(kNumPossibleRegions)" ")"
, v1, v2); } while (false)
;
290 return res;
291 }
292
293 uptr ComputeRegionBeg(uptr mem) {
294 return mem & ~(kRegionSize - 1);
295 }
296
297 uptr AllocateRegion(AllocatorStats *stat, uptr class_id) {
298 DCHECK_LT(class_id, kNumClasses);
299 const uptr res = reinterpret_cast<uptr>(MmapAlignedOrDieOnFatalError(
300 kRegionSize, kRegionSize, PrimaryAllocatorName));
301 if (UNLIKELY(!res)__builtin_expect(!!(!res), 0))
302 return 0;
303 MapUnmapCallback().OnMap(res, kRegionSize);
304 stat->Add(AllocatorStatMapped, kRegionSize);
305 CHECK(IsAligned(res, kRegionSize))do { __sanitizer::u64 v1 = (__sanitizer::u64)((IsAligned(res,
kRegionSize))); __sanitizer::u64 v2 = (__sanitizer::u64)(0);
if (__builtin_expect(!!(!(v1 != v2)), 0)) __sanitizer::CheckFailed
("/build/llvm-toolchain-snapshot-10~svn374877/projects/compiler-rt/lib/scudo/../sanitizer_common/sanitizer_allocator_primary32.h"
, 305, "(" "(IsAligned(res, kRegionSize))" ") " "!=" " (" "0"
")", v1, v2); } while (false)
;
306 possible_regions.set(ComputeRegionId(res), static_cast<u8>(class_id));
307 return res;
308 }
309
310 SizeClassInfo *GetSizeClassInfo(uptr class_id) {
311 DCHECK_LT(class_id, kNumClasses);
312 return &size_class_info_array[class_id];
313 }
314
315 bool PopulateBatches(AllocatorCache *c, SizeClassInfo *sci, uptr class_id,
316 TransferBatch **current_batch, uptr max_count,
317 uptr *pointers_array, uptr count) {
318 // If using a separate class for batches, we do not need to shuffle it.
319 if (kRandomShuffleChunks && (!kUseSeparateSizeClassForBatch ||
320 class_id != SizeClassMap::kBatchClassID))
321 RandomShuffle(pointers_array, count, &sci->rand_state);
322 TransferBatch *b = *current_batch;
323 for (uptr i = 0; i < count; i++) {
324 if (!b) {
325 b = c->CreateBatch(class_id, this, (TransferBatch*)pointers_array[i]);
326 if (UNLIKELY(!b)__builtin_expect(!!(!b), 0))
327 return false;
328 b->Clear();
329 }
330 b->Add((void*)pointers_array[i]);
331 if (b->Count() == max_count) {
332 sci->free_list.push_back(b);
333 b = nullptr;
334 }
335 }
336 *current_batch = b;
337 return true;
338 }
339
340 bool PopulateFreeList(AllocatorStats *stat, AllocatorCache *c,
341 SizeClassInfo *sci, uptr class_id) {
342 const uptr region = AllocateRegion(stat, class_id);
343 if (UNLIKELY(!region)__builtin_expect(!!(!region), 0))
344 return false;
345 if (kRandomShuffleChunks)
346 if (UNLIKELY(sci->rand_state == 0)__builtin_expect(!!(sci->rand_state == 0), 0))
347 // The random state is initialized from ASLR (PIE) and time.
348 sci->rand_state = reinterpret_cast<uptr>(sci) ^ NanoTime();
349 const uptr size = ClassIdToSize(class_id);
350 const uptr n_chunks = kRegionSize / (size + kMetadataSize);
351 const uptr max_count = TransferBatch::MaxCached(size);
352 DCHECK_GT(max_count, 0);
353 TransferBatch *b = nullptr;
354 constexpr uptr kShuffleArraySize = 48;
355 uptr shuffle_array[kShuffleArraySize];
356 uptr count = 0;
357 for (uptr i = region; i < region + n_chunks * size; i += size) {
358 shuffle_array[count++] = i;
359 if (count == kShuffleArraySize) {
360 if (UNLIKELY(!PopulateBatches(c, sci, class_id, &b, max_count,__builtin_expect(!!(!PopulateBatches(c, sci, class_id, &b
, max_count, shuffle_array, count)), 0)
361 shuffle_array, count))__builtin_expect(!!(!PopulateBatches(c, sci, class_id, &b
, max_count, shuffle_array, count)), 0)
)
362 return false;
363 count = 0;
364 }
365 }
366 if (count) {
367 if (UNLIKELY(!PopulateBatches(c, sci, class_id, &b, max_count,__builtin_expect(!!(!PopulateBatches(c, sci, class_id, &b
, max_count, shuffle_array, count)), 0)
368 shuffle_array, count))__builtin_expect(!!(!PopulateBatches(c, sci, class_id, &b
, max_count, shuffle_array, count)), 0)
)
369 return false;
370 }
371 if (b) {
372 CHECK_GT(b->Count(), 0)do { __sanitizer::u64 v1 = (__sanitizer::u64)((b->Count())
); __sanitizer::u64 v2 = (__sanitizer::u64)((0)); if (__builtin_expect
(!!(!(v1 > v2)), 0)) __sanitizer::CheckFailed("/build/llvm-toolchain-snapshot-10~svn374877/projects/compiler-rt/lib/scudo/../sanitizer_common/sanitizer_allocator_primary32.h"
, 372, "(" "(b->Count())" ") " ">" " (" "(0)" ")", v1, v2
); } while (false)
;
373 sci->free_list.push_back(b);
374 }
375 return true;
376 }
377
378 ByteMap possible_regions;
379 SizeClassInfo size_class_info_array[kNumClasses];
380};

/build/llvm-toolchain-snapshot-10~svn374877/projects/compiler-rt/lib/scudo/../sanitizer_common/sanitizer_allocator_size_class_map.h

1//===-- sanitizer_allocator_size_class_map.h --------------------*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// Part of the Sanitizer Allocator.
10//
11//===----------------------------------------------------------------------===//
12#ifndef SANITIZER_ALLOCATOR_H
13#error This file must be included inside sanitizer_allocator.h
14#endif
15
16// SizeClassMap maps allocation sizes into size classes and back.
17// Class 0 always corresponds to size 0.
18// The other sizes are controlled by the template parameters:
19// kMinSizeLog: defines the class 1 as 2^kMinSizeLog.
20// kMaxSizeLog: defines the last class as 2^kMaxSizeLog.
21// kMidSizeLog: the classes starting from 1 increase with step
22// 2^kMinSizeLog until 2^kMidSizeLog.
23// kNumBits: the number of non-zero bits in sizes after 2^kMidSizeLog.
24// E.g. with kNumBits==3 all size classes after 2^kMidSizeLog
25// look like 0b1xx0..0, where x is either 0 or 1.
26//
27// Example: kNumBits=3, kMidSizeLog=4, kMidSizeLog=8, kMaxSizeLog=17:
28//
29// Classes 1 - 16 correspond to sizes 16 to 256 (size = class_id * 16).
30// Next 4 classes: 256 + i * 64 (i = 1 to 4).
31// Next 4 classes: 512 + i * 128 (i = 1 to 4).
32// ...
33// Next 4 classes: 2^k + i * 2^(k-2) (i = 1 to 4).
34// Last class corresponds to kMaxSize = 1 << kMaxSizeLog.
35//
36// This structure of the size class map gives us:
37// - Efficient table-free class-to-size and size-to-class functions.
38// - Difference between two consequent size classes is between 14% and 25%
39//
40// This class also gives a hint to a thread-caching allocator about the amount
41// of chunks that need to be cached per-thread:
42// - kMaxNumCachedHint is a hint for maximal number of chunks per size class.
43// The actual number is computed in TransferBatch.
44// - (1 << kMaxBytesCachedLog) is the maximal number of bytes per size class.
45//
46// Part of output of SizeClassMap::Print():
47// c00 => s: 0 diff: +0 00% l 0 cached: 0 0; id 0
48// c01 => s: 16 diff: +16 00% l 4 cached: 256 4096; id 1
49// c02 => s: 32 diff: +16 100% l 5 cached: 256 8192; id 2
50// c03 => s: 48 diff: +16 50% l 5 cached: 256 12288; id 3
51// c04 => s: 64 diff: +16 33% l 6 cached: 256 16384; id 4
52// c05 => s: 80 diff: +16 25% l 6 cached: 256 20480; id 5
53// c06 => s: 96 diff: +16 20% l 6 cached: 256 24576; id 6
54// c07 => s: 112 diff: +16 16% l 6 cached: 256 28672; id 7
55//
56// c08 => s: 128 diff: +16 14% l 7 cached: 256 32768; id 8
57// c09 => s: 144 diff: +16 12% l 7 cached: 256 36864; id 9
58// c10 => s: 160 diff: +16 11% l 7 cached: 256 40960; id 10
59// c11 => s: 176 diff: +16 10% l 7 cached: 256 45056; id 11
60// c12 => s: 192 diff: +16 09% l 7 cached: 256 49152; id 12
61// c13 => s: 208 diff: +16 08% l 7 cached: 256 53248; id 13
62// c14 => s: 224 diff: +16 07% l 7 cached: 256 57344; id 14
63// c15 => s: 240 diff: +16 07% l 7 cached: 256 61440; id 15
64//
65// c16 => s: 256 diff: +16 06% l 8 cached: 256 65536; id 16
66// c17 => s: 320 diff: +64 25% l 8 cached: 204 65280; id 17
67// c18 => s: 384 diff: +64 20% l 8 cached: 170 65280; id 18
68// c19 => s: 448 diff: +64 16% l 8 cached: 146 65408; id 19
69//
70// c20 => s: 512 diff: +64 14% l 9 cached: 128 65536; id 20
71// c21 => s: 640 diff: +128 25% l 9 cached: 102 65280; id 21
72// c22 => s: 768 diff: +128 20% l 9 cached: 85 65280; id 22
73// c23 => s: 896 diff: +128 16% l 9 cached: 73 65408; id 23
74//
75// c24 => s: 1024 diff: +128 14% l 10 cached: 64 65536; id 24
76// c25 => s: 1280 diff: +256 25% l 10 cached: 51 65280; id 25
77// c26 => s: 1536 diff: +256 20% l 10 cached: 42 64512; id 26
78// c27 => s: 1792 diff: +256 16% l 10 cached: 36 64512; id 27
79//
80// ...
81//
82// c48 => s: 65536 diff: +8192 14% l 16 cached: 1 65536; id 48
83// c49 => s: 81920 diff: +16384 25% l 16 cached: 1 81920; id 49
84// c50 => s: 98304 diff: +16384 20% l 16 cached: 1 98304; id 50
85// c51 => s: 114688 diff: +16384 16% l 16 cached: 1 114688; id 51
86//
87// c52 => s: 131072 diff: +16384 14% l 17 cached: 1 131072; id 52
88//
89//
90// Another example (kNumBits=2):
91// c00 => s: 0 diff: +0 00% l 0 cached: 0 0; id 0
92// c01 => s: 32 diff: +32 00% l 5 cached: 64 2048; id 1
93// c02 => s: 64 diff: +32 100% l 6 cached: 64 4096; id 2
94// c03 => s: 96 diff: +32 50% l 6 cached: 64 6144; id 3
95// c04 => s: 128 diff: +32 33% l 7 cached: 64 8192; id 4
96// c05 => s: 160 diff: +32 25% l 7 cached: 64 10240; id 5
97// c06 => s: 192 diff: +32 20% l 7 cached: 64 12288; id 6
98// c07 => s: 224 diff: +32 16% l 7 cached: 64 14336; id 7
99// c08 => s: 256 diff: +32 14% l 8 cached: 64 16384; id 8
100// c09 => s: 384 diff: +128 50% l 8 cached: 42 16128; id 9
101// c10 => s: 512 diff: +128 33% l 9 cached: 32 16384; id 10
102// c11 => s: 768 diff: +256 50% l 9 cached: 21 16128; id 11
103// c12 => s: 1024 diff: +256 33% l 10 cached: 16 16384; id 12
104// c13 => s: 1536 diff: +512 50% l 10 cached: 10 15360; id 13
105// c14 => s: 2048 diff: +512 33% l 11 cached: 8 16384; id 14
106// c15 => s: 3072 diff: +1024 50% l 11 cached: 5 15360; id 15
107// c16 => s: 4096 diff: +1024 33% l 12 cached: 4 16384; id 16
108// c17 => s: 6144 diff: +2048 50% l 12 cached: 2 12288; id 17
109// c18 => s: 8192 diff: +2048 33% l 13 cached: 2 16384; id 18
110// c19 => s: 12288 diff: +4096 50% l 13 cached: 1 12288; id 19
111// c20 => s: 16384 diff: +4096 33% l 14 cached: 1 16384; id 20
112// c21 => s: 24576 diff: +8192 50% l 14 cached: 1 24576; id 21
113// c22 => s: 32768 diff: +8192 33% l 15 cached: 1 32768; id 22
114// c23 => s: 49152 diff: +16384 50% l 15 cached: 1 49152; id 23
115// c24 => s: 65536 diff: +16384 33% l 16 cached: 1 65536; id 24
116// c25 => s: 98304 diff: +32768 50% l 16 cached: 1 98304; id 25
117// c26 => s: 131072 diff: +32768 33% l 17 cached: 1 131072; id 26
118
119template <uptr kNumBits, uptr kMinSizeLog, uptr kMidSizeLog, uptr kMaxSizeLog,
120 uptr kMaxNumCachedHintT, uptr kMaxBytesCachedLog>
121class SizeClassMap {
122 static const uptr kMinSize = 1 << kMinSizeLog;
123 static const uptr kMidSize = 1 << kMidSizeLog;
124 static const uptr kMidClass = kMidSize / kMinSize;
125 static const uptr S = kNumBits - 1;
126 static const uptr M = (1 << S) - 1;
127
128 public:
129 // kMaxNumCachedHintT is a power of two. It serves as a hint
130 // for the size of TransferBatch, the actual size could be a bit smaller.
131 static const uptr kMaxNumCachedHint = kMaxNumCachedHintT;
132 COMPILER_CHECK((kMaxNumCachedHint & (kMaxNumCachedHint - 1)) == 0)typedef char assertion_failed__132[2*(int)((kMaxNumCachedHint
& (kMaxNumCachedHint - 1)) == 0)-1]
;
133
134 static const uptr kMaxSize = 1UL << kMaxSizeLog;
135 static const uptr kNumClasses =
136 kMidClass + ((kMaxSizeLog - kMidSizeLog) << S) + 1 + 1;
137 static const uptr kLargestClassID = kNumClasses - 2;
138 static const uptr kBatchClassID = kNumClasses - 1;
139 COMPILER_CHECK(kNumClasses >= 16 && kNumClasses <= 256)typedef char assertion_failed__139[2*(int)(kNumClasses >= 16
&& kNumClasses <= 256)-1]
;
140 static const uptr kNumClassesRounded =
141 kNumClasses <= 32 ? 32 :
142 kNumClasses <= 64 ? 64 :
143 kNumClasses <= 128 ? 128 : 256;
144
145 static uptr Size(uptr class_id) {
146 // Estimate the result for kBatchClassID because this class does not know
147 // the exact size of TransferBatch. It's OK since we are using the actual
148 // sizeof(TransferBatch) where it matters.
149 if (UNLIKELY
27.1
'class_id' is not equal to 'kBatchClassID'
27.1
'class_id' is not equal to 'kBatchClassID'
27.1
'class_id' is not equal to 'kBatchClassID'
(class_id == kBatchClassID)__builtin_expect(!!(class_id == kBatchClassID), 0)
)
28
Taking false branch
150 return kMaxNumCachedHint * sizeof(uptr);
151 if (class_id <= kMidClass)
29
Assuming 'class_id' is > 'kMidClass'
30
Taking false branch
152 return kMinSize * class_id;
153 class_id -= kMidClass;
154 uptr t = kMidSize << (class_id >> S);
31
The result of the left shift is undefined due to shifting '256' by '1073741820', which is unrepresentable in the unsigned version of the return type '__sanitizer::uptr'
155 return t + (t >> S) * (class_id & M);
156 }
157
158 static uptr ClassID(uptr size) {
159 if (UNLIKELY(size > kMaxSize)__builtin_expect(!!(size > kMaxSize), 0))
160 return 0;
161 if (size <= kMidSize)
162 return (size + kMinSize - 1) >> kMinSizeLog;
163 const uptr l = MostSignificantSetBitIndex(size);
164 const uptr hbits = (size >> (l - S)) & M;
165 const uptr lbits = size & ((1U << (l - S)) - 1);
166 const uptr l1 = l - kMidSizeLog;
167 return kMidClass + (l1 << S) + hbits + (lbits > 0);
168 }
169
170 static uptr MaxCachedHint(uptr size) {
171 DCHECK_LE(size, kMaxSize);
172 if (UNLIKELY(size == 0)__builtin_expect(!!(size == 0), 0))
173 return 0;
174 uptr n;
175 // Force a 32-bit division if the template parameters allow for it.
176 if (kMaxBytesCachedLog > 31 || kMaxSizeLog > 31)
177 n = (1UL << kMaxBytesCachedLog) / size;
178 else
179 n = (1U << kMaxBytesCachedLog) / static_cast<u32>(size);
180 return Max<uptr>(1U, Min(kMaxNumCachedHint, n));
181 }
182
183 static void Print() {
184 uptr prev_s = 0;
185 uptr total_cached = 0;
186 for (uptr i = 0; i < kNumClasses; i++) {
187 uptr s = Size(i);
188 if (s >= kMidSize / 2 && (s & (s - 1)) == 0)
189 Printf("\n");
190 uptr d = s - prev_s;
191 uptr p = prev_s ? (d * 100 / prev_s) : 0;
192 uptr l = s ? MostSignificantSetBitIndex(s) : 0;
193 uptr cached = MaxCachedHint(s) * s;
194 if (i == kBatchClassID)
195 d = p = l = 0;
196 Printf("c%02zd => s: %zd diff: +%zd %02zd%% l %zd "
197 "cached: %zd %zd; id %zd\n",
198 i, Size(i), d, p, l, MaxCachedHint(s), cached, ClassID(s));
199 total_cached += cached;
200 prev_s = s;
201 }
202 Printf("Total cached: %zd\n", total_cached);
203 }
204
205 static void Validate() {
206 for (uptr c = 1; c < kNumClasses; c++) {
207 // Printf("Validate: c%zd\n", c);
208 uptr s = Size(c);
209 CHECK_NE(s, 0U)do { __sanitizer::u64 v1 = (__sanitizer::u64)((s)); __sanitizer
::u64 v2 = (__sanitizer::u64)((0U)); if (__builtin_expect(!!(
!(v1 != v2)), 0)) __sanitizer::CheckFailed("/build/llvm-toolchain-snapshot-10~svn374877/projects/compiler-rt/lib/scudo/../sanitizer_common/sanitizer_allocator_size_class_map.h"
, 209, "(" "(s)" ") " "!=" " (" "(0U)" ")", v1, v2); } while (
false)
;
210 if (c == kBatchClassID)
211 continue;
212 CHECK_EQ(ClassID(s), c)do { __sanitizer::u64 v1 = (__sanitizer::u64)((ClassID(s))); __sanitizer
::u64 v2 = (__sanitizer::u64)((c)); if (__builtin_expect(!!(!
(v1 == v2)), 0)) __sanitizer::CheckFailed("/build/llvm-toolchain-snapshot-10~svn374877/projects/compiler-rt/lib/scudo/../sanitizer_common/sanitizer_allocator_size_class_map.h"
, 212, "(" "(ClassID(s))" ") " "==" " (" "(c)" ")", v1, v2); }
while (false)
;
213 if (c < kLargestClassID)
214 CHECK_EQ(ClassID(s + 1), c + 1)do { __sanitizer::u64 v1 = (__sanitizer::u64)((ClassID(s + 1)
)); __sanitizer::u64 v2 = (__sanitizer::u64)((c + 1)); if (__builtin_expect
(!!(!(v1 == v2)), 0)) __sanitizer::CheckFailed("/build/llvm-toolchain-snapshot-10~svn374877/projects/compiler-rt/lib/scudo/../sanitizer_common/sanitizer_allocator_size_class_map.h"
, 214, "(" "(ClassID(s + 1))" ") " "==" " (" "(c + 1)" ")", v1
, v2); } while (false)
;
215 CHECK_EQ(ClassID(s - 1), c)do { __sanitizer::u64 v1 = (__sanitizer::u64)((ClassID(s - 1)
)); __sanitizer::u64 v2 = (__sanitizer::u64)((c)); if (__builtin_expect
(!!(!(v1 == v2)), 0)) __sanitizer::CheckFailed("/build/llvm-toolchain-snapshot-10~svn374877/projects/compiler-rt/lib/scudo/../sanitizer_common/sanitizer_allocator_size_class_map.h"
, 215, "(" "(ClassID(s - 1))" ") " "==" " (" "(c)" ")", v1, v2
); } while (false)
;
216 CHECK_GT(Size(c), Size(c - 1))do { __sanitizer::u64 v1 = (__sanitizer::u64)((Size(c))); __sanitizer
::u64 v2 = (__sanitizer::u64)((Size(c - 1))); if (__builtin_expect
(!!(!(v1 > v2)), 0)) __sanitizer::CheckFailed("/build/llvm-toolchain-snapshot-10~svn374877/projects/compiler-rt/lib/scudo/../sanitizer_common/sanitizer_allocator_size_class_map.h"
, 216, "(" "(Size(c))" ") " ">" " (" "(Size(c - 1))" ")", v1
, v2); } while (false)
;
217 }
218 CHECK_EQ(ClassID(kMaxSize + 1), 0)do { __sanitizer::u64 v1 = (__sanitizer::u64)((ClassID(kMaxSize
+ 1))); __sanitizer::u64 v2 = (__sanitizer::u64)((0)); if (__builtin_expect
(!!(!(v1 == v2)), 0)) __sanitizer::CheckFailed("/build/llvm-toolchain-snapshot-10~svn374877/projects/compiler-rt/lib/scudo/../sanitizer_common/sanitizer_allocator_size_class_map.h"
, 218, "(" "(ClassID(kMaxSize + 1))" ") " "==" " (" "(0)" ")"
, v1, v2); } while (false)
;
219
220 for (uptr s = 1; s <= kMaxSize; s++) {
221 uptr c = ClassID(s);
222 // Printf("s%zd => c%zd\n", s, c);
223 CHECK_LT(c, kNumClasses)do { __sanitizer::u64 v1 = (__sanitizer::u64)((c)); __sanitizer
::u64 v2 = (__sanitizer::u64)((kNumClasses)); if (__builtin_expect
(!!(!(v1 < v2)), 0)) __sanitizer::CheckFailed("/build/llvm-toolchain-snapshot-10~svn374877/projects/compiler-rt/lib/scudo/../sanitizer_common/sanitizer_allocator_size_class_map.h"
, 223, "(" "(c)" ") " "<" " (" "(kNumClasses)" ")", v1, v2
); } while (false)
;
224 CHECK_GE(Size(c), s)do { __sanitizer::u64 v1 = (__sanitizer::u64)((Size(c))); __sanitizer
::u64 v2 = (__sanitizer::u64)((s)); if (__builtin_expect(!!(!
(v1 >= v2)), 0)) __sanitizer::CheckFailed("/build/llvm-toolchain-snapshot-10~svn374877/projects/compiler-rt/lib/scudo/../sanitizer_common/sanitizer_allocator_size_class_map.h"
, 224, "(" "(Size(c))" ") " ">=" " (" "(s)" ")", v1, v2); }
while (false)
;
225 if (c > 0)
226 CHECK_LT(Size(c - 1), s)do { __sanitizer::u64 v1 = (__sanitizer::u64)((Size(c - 1)));
__sanitizer::u64 v2 = (__sanitizer::u64)((s)); if (__builtin_expect
(!!(!(v1 < v2)), 0)) __sanitizer::CheckFailed("/build/llvm-toolchain-snapshot-10~svn374877/projects/compiler-rt/lib/scudo/../sanitizer_common/sanitizer_allocator_size_class_map.h"
, 226, "(" "(Size(c - 1))" ") " "<" " (" "(s)" ")", v1, v2
); } while (false)
;
227 }
228 }
229};
230
231typedef SizeClassMap<3, 4, 8, 17, 128, 16> DefaultSizeClassMap;
232typedef SizeClassMap<3, 4, 8, 17, 64, 14> CompactSizeClassMap;
233typedef SizeClassMap<2, 5, 9, 16, 64, 14> VeryCompactSizeClassMap;
234
235// The following SizeClassMap only holds a way small number of cached entries,
236// allowing for denser per-class arrays, smaller memory footprint and usually
237// better performances in threaded environments.
238typedef SizeClassMap<3, 4, 8, 17, 8, 10> DenseSizeClassMap;
239// Similar to VeryCompact map above, this one has a small number of different
240// size classes, and also reduced thread-local caches.
241typedef SizeClassMap<2, 5, 9, 16, 8, 10> VeryDenseSizeClassMap;